Re: [firebird-support] Multi-Version Consistent Read Question

2011-12-14 Thread Norman Dunbar
Morning Ann, On 13/12/11 18:18, Ann Harrison wrote: ... The method used by Oracle (and MySQL's InnoDB) keeps old versions in log files which are purged periodically. A long running transaction can get inconsistent data if the log file that contained the record version appropriate for it has

Re: [firebird-support] Multi-Version Consistent Read Question

2011-12-14 Thread Ann Harrison
And a different good morning to you Norman, If I may be so bold Of course, and thank you for the detailed and complete description of a mechanism I glossed over irresponsibly. As long as the DBA correctly sizes the UNDO tablespace and correctly sets the UNDO_RETENTION parameter to a

Re: [firebird-support] Multi-Version Consistent Read Question

2011-12-14 Thread nor...@dunbar-it.co.uk
Ann Harrison aharri...@ibphoenix.com wrote: And a different good morning to you Norman, And already it's evening. :-) Of course, and thank you for the detailed and complete description of a mechanism I glossed over irresponsibly. Welcome. You may be surprised at how many people think that Oracle

[firebird-support] Multi-Version Consistent Read Question

2011-12-13 Thread Joey S.
Hello, I am researching methods to achieve high throughput for a learning chat application I am designing as a self-led student. I came across the Multiversion Control method of ACID and have a theoretical question: though it seems remote that a reader of data wouldn't get an old read what has

Re: [firebird-support] Multi-Version Consistent Read Question

2011-12-13 Thread Alexey Kovyazin
Hello Joey, Can you please tell in what university you are studying? Why you have chosen Firebird - was it some recommendation? Regards, Alexey Kovyazin Hello, I am researching methods to achieve high throughput for a learning chat application I am designing as a self-led student. I came

Re: [firebird-support] Multi-Version Consistent Read Question

2011-12-13 Thread Helen Borrie
At 03:39 AM 14/12/2011, Joey S. wrote: Hello, I am researching methods to achieve high throughput for a learning chat application I am designing as a self-led student. I came across the Multiversion Control method of ACID and have a theoretical question: though it seems remote that a reader of